Browse Prior Art Database

Two Phase Type Phase Control Power Supply

IP.com Disclosure Number: IPCOM000076602D
Original Publication Date: 1972-Mar-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 3 page(s) / 50K

Publishing Venue

IBM

Related People

Wenda, RL: AUTHOR

Abstract

Power supply 10 provides less ripple and better component utilization than standard single-phase types of phase-control power supplies.

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Two Phase Type Phase Control Power Supply

Power supply 10 provides less ripple and better component utilization than standard single-phase types of phase-control power supplies.

Two alternating-current voltages Vab, Vbc, are supplied across the input terminals A, B, C, c.f. Fig. 1. The voltages Vab and Vbc are phase shifted with respect to each other, as shown in Fig. 2. By way of example, the wave shapes of Vab and Vbc are assumed to be sinusoidal and have a phase shift of 120 degrees with respect to each other. Voltage Vab is applied to the primary winding 11 of transformer T1 which induces a similar voltage in secondary winding 12-13. This secondary voltage is full-wave rectified by diodes D1-D2 and applied to terminals X-Y.

Simultaneously, the voltage Vbc is applied to the primary winding 14 of transformer T2. Transformer T2, silicon-control rectifiers S1 and S2, and gets signal control circuit 17 are configured as a standard. single-phase, full-wave phase-control power supply.

Vdiode, c. f. Fig. 2, is the waveform produced at terminals X, Y by the full- wave rectifier (D1-D2) portion of the circuit 10. Vscr is the waveform produced at terminal X, Y by the single-phase, full-wave, phase-control portion of circuit 10. Vxy produced at terminal X, Y is the waveform resulting from the superposition of Vdiode and Vscr. In Fig. 2, waveforms Vxy and Vsr are shown for various gating delay angles phi.

More particularly, selectively controlled different gating angles phi are provided by the gating pulses s of circuit 17. A gating delay angle is defined as the time delay from the point where the rectifiers S1, S2 would conduct if there were ordinary diodes like D1, D2 to the point where the rectifiers S1, S2 are gated to an ON condition.

The magnitudes of the secondary voltages of transformers T1, T2 are independent of each other. By way of example, the magnitude of the secondary voltage of transformer T1 is assumed to be one and a half times the magnitude of the secondary voltage of transformer T1. This provides a change in the average value of Vxy of 1.75 to 1 as the gating delay angle phi is changed from phi min to phi max.

The actual output signal Vxy is shown in Fig. 2 for the different gating delay angles of phi min, 60 degrees, 90 degrees, and degrees. The value of Vxy at any instant is t...